Invision 352 MPa Plus

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I purchased an Invision 352 MPa Plus system about 2 months ago and I have been trying to get the pulse settings working right. I have been through all the forums looking for answers, and I have ordered Millers publications. I know what pulse is, I have been welding a long time and want to use the pulse to reduce distortion on welding stainless steel. I build custom small to medium tanks (up to 10,000 gal) from time to time and I want to use the machine to the best of its ability. When I bought the machine, I was running 98/2 Ox and when I sprayed, it would hiss. Now I can not get that hiss back after (what I believe was) a bottle change, I have ran through 5 bottles now and can't be sure. Obviously it could be the bottle not filled right. I youtube'd pulse welding and seen a short video of a guy pulsing on vertical T and a flat lap joint. I paid more attention to the hissing/pulsing sound since I can relate to this. Also I have searched online sites for someone else with an Invision 352 MPa Plus system, but apparently I am like the only one with this machine. My questions are:Is pulse spray used with heavier then normal wire to create that pinch effect w/o a fast paced WFS?In doing pretty custom SS tanks, which tri mix is best for pulsing. I know what the book says, looking for what real experience from you all say.I don't like having little control over the machine like pulse tig. I like being able to set the settings myself, but this is all computer controlled.Running it with Pulse on Steel 1/2" I'm running an ARCL of 83 with .045 WFS of I think 333. I am not getting a pulsing sound. It is trying to, but I can't get it close enough. When I ran on 1/8" SS 316L w/ 316L, .035 He/Ar/Co or 98/2 Ox, I was getting the same results, but no where close to pulse. I tried almost every ARCL w/ WFS adjusting ARCL in 2 increments, and WFS adjusting in 20's after running through the ARCL for that WFS.Fred,P.S. long time listener, first time caller.....
Reply:Update: I just went out and put the .045 wire on the reel with 98/2 ox, ARCL 35 w/ WFS 165 on 1/4" steel, Sharp Arc at 35 on flat plate and it came out pretty good. In my earlier post, I apparently answered my own question. If my assumption is correct, pulse does require a heavier wire since you can't pulse at 500 IPM (guessing w/ .030) it just doesn't give the machine enough time to pulse.My goal is to use the pulse as much as possible (to reduce spatter mainly) on thinner materials (1/4- 14 ga) since the competitive edge is reducing labor efforts and cleaning up welds is time consuming.Edit: I am asking you since my LWS hands out brochures, and I can't ask anyone about a machine that has been on the market for less then a year. I also do have a dynasty 350 that I don't have a problem with pulsing, so I may be an old fart, but I do use my head and can read. Also, please don't PM me saying I should have bought a 350-P, you don't know my setup and if you did you would agree with me buying a smaller portable system, you can't suspend a 350-P from a overhead custom built trolley that can move anywhere in a 60x60 shop without moving the power source. Think bridge crane but using a feeder instead of a hook.Last edited by Portable Fred; 05-24-2011 at 09:31 AM.
Reply:I can't comment on the 352 directly, I have the 350P which I think is basically the built in wire feeder version).Miller does have some books on pulse mig but its mainly focused on their older style MIGs.For now, follow manual's recommendation on gas.  Once setup, pulse is a bit more forgiving because the machine will keep the voltages were they need to be for the wire speed.  You can put down metal over a much broader wire speed setting.  There are of course limits.With aluminum I have run as high as 450ipm with .035 wire with no problems.  You should have a setting for different wire sizes.  (read the manual)Smooth wire feed is critical.  If the rollers slip, the power supply doesn't sense this and you will get an unstable arc.  It is possible that when you switched to .045 you fixed a feed issue.Most people tend to like arc length shorter than what the manual recommends.  Arc length is effectively your voltage adjustment (call it base voltage).  Myself included come from a background of short arc welding - I suspect shorter arc lengths are just more comfortable.Under normal spray, the arc length is relatively big.  With pulse, you have full control over arc length and even if you work distance changes, the arc length will stay the same..... assume your wire feed speed is steady.The manual's pictures show a triangle with a stick on it.  When everything is working right, you should see the wire disappear into an arc that looks amazingly like a cone/triangle.  I always think it looks like mini spray painting.  Bottom line it looks just like the stick figure picture in the manual.  If you see the arc length changing or see the wire hitting the work piece or getting burn back, you have something wrong.Pulse is really good on aluminum because it allows out of position work.  If you normally have to spray, you will find out of position is easier.  I don't MIG stainless so I'll take your word for it being better.  Personally I like the control of short arc on steel better.If you have an arc-force setting... on the 350P this is effectively the frequency adjustment.  Higher frequency gives a more focused arc.  On outside corners I tend to turn the frequency down a smidge (on the 350P its 0-50 and I use 15-20 on outside corners, 25-35 for everything else.If you look at the manual, I think you will find that on thinner stuff, the wire speed is lower than if you were using short-arc.  On thicker stuff, say 1/4 and up, wire speed is actually higher than short arc (at least aluminum).  This tells me the internal program is setup to put less heat in thinner gauge stuff, but potentially more heat (like spray transfer) on the thicker stuff.To add heat, you turn up the wire speed.  If its running to hot, turn it down.  Once you have it dial in for your style of welding, that's all you have to do.  If your buddy comes over an asks you to weld something, all you have to do is guess-timate the wire speed.  Done.Con Fuse!Miller Dynasty 350Millermatic 350P-Spoolmatic 30AMiller Multimatic 200Hypertherm PowerMax 1000G3Miller Maxstar 200DX
Reply:Hi Fred, I also have an invision 352 MPA setup, though I have not had time to work on the pulse settings. Since you are working on them, could you post them or PM me your number so I can talk with you about it.Thank you